This invention relates generally to the field of orthopedic appliances used to presurgically ameliorate congenital cleft lip deformities in infants by the application of direct controlled molding forces, such appliances often referred to as nasoalveolar molding (NAM) appliances, as well as to methods of correcting cleft lips using such NAM appliances.
A key component of the cleft lip deformity is nasal asymmetry and abnormal form. Current surgical techniques can achieve limited correction. Pre-surgical nasal molding has become popular in large cleft centers in an attempt to minimize the nasal deformity prior to surgery. Unlike adult cartilage, the nasal cartilages of an infant are responsive to external molding pressures and will pemanently change shape. The most common pre-surgical treatment (nasoalveolar molding) now in use is limited to linear molding changes on the nostrils, and requires an oral splint for stabilization of the nasal molding component. The traditional NAM treatment protocol requires weekly visits to the orthodontist over the first three months of life of the infant for progressive manual adjustment of the NAM device to alter the molding forces on the infant's alveolus and nasal anatomy. The traditional NAM device relies on taping across the base of the nose to achieve medial movement of the lateral crura and alar bases, and a separate pressure post based on an acrylic oral splint to fit inside the nostril and lift the nasal tip. Limitations of this existing technique are that the taping force is extremely variable in achieving the desired result, can distort the upper lip, and since the upward force is more powerful than the taping, an enlarged, iatrogenic triangulated nostril deformity can result.
Improved methodologies and nasal molding devices are disclosed in U.S. Pat. No. 9,486,353 to Hopper, U.S. Pat. No. 8,323,308 to Hopper and U.S. Pat. No. 8,523,896 to Hopper, in which a dynamic NAM device is disclosed. The device in a main embodiment comprises a pair of rotation assemblies each having an internal shaping member for insertion in a nostril and an external shaping member to be positioned externally to the nostril, wherein the internal and external shaping members are progressively incrementally pivoted about the rotation assemblies, while simultaneously the separation distance between the rotation assemblies is incrementally decreased by reducing the angular separation about a centralized assembly, thereby molding the nasal anatomy into the desired shape over time. The device requires mechanisms to lock the angular positioning of the centralized assembly and the rotational positioning of the external/internal shaping members. Furthermore, the device requires multiple manual adjustments over the course of time.
It is an object of this invention to provide a device and a method that addresses the problems encountered in the known devices and methods for presurgical molding and shaping of anatomical members distorted or improperly formed due to the presence of a cleft lip. It is a further object to provide a spring-biased nasal molding device that imparts a three-dimensional rotational change in nasal morphology in preparation for corrective surgery, which device is self-retaining and self-supporting due to opposing tension across the nose, to rotate the lateral crura and alar crease of the lower lateral cartilages of the nose medially and superiorly, while simultaneously elevating the genu and soft triangle of the nasal tip superiorly, with the simultaneous, coordinated and progressive rotational molding of the nostril width and height precluding nasal aperture distortion or enlargement. It is a further object to provide such a device that automatically and continuously provides the shaping force without need for manual adjustment after placement in the nasal anatomical members. It is a further object to provide such a device wherein the shaping force is produced by a unitary biasing member composed of a polymer material and comprising a spring segment, a pair of intra-nasal projecting members and a pair of extra-nasal arm members, with the device further comprising a cover member disposed on each of the extra-nasal arm members and a stent member disposed on each of the intra-nasal projecting members.